Tracking camera device

ABSTRACT

An integrated data detecting circuit  14  integrates digital data for each of detecting blocks set within a movement detecting area. A tripod-head control circuit  16  detects a correlation value for this integrated data to previously-registered integrated data, and compares the correlation value with a threshold to determine a first detecting block corresponding to an object. The tripod-head control circuit  16  further determines a first detecting area including the most first detecting blocks among a plurality of detecting areas set in the movement detecting area, and supplies to a drive device  18  a tripod-head control signal corresponding to the position. Accordingly, the drive device  18  controls a tripod head  20  such that a camera  12  is shifted in position to a direction of the first detecting area. Since determination is made for a first detecting area including the most first detecting blocks, the camera can be stabilized when an object is moving finely.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to tracking camera devices, and moreparticularly to a tracking camera device adapted to track an object thatis imaged by a camera and captured at a detecting area thereof.

2. Description of the Related Art

There is one example of a tracking camera device to track an object thatis imaged by a camera and captured within an detecting area, proposed inJapanese Patent Application No. H6-267347 applied for patent on Oct. 31,1994. This technology involves a process of detecting a detecting blockto be considered the same in color as a particular detecting block amonga plurality of detecting blocks set within a motion vector detectingarea. A motion vector for the object is estimated depending upon aweight center of the same-colored detecting block, thereby tracking theobject according to the motion vector.

In such prior art, however, even where the object is finely movingwithin the motion vector detecting area, the camera will track theobject in response to the movement thereof, resulting in a problem thatthe camera is placed unstable in position.

SUMMARY OF THE INVENTION

The present invention is, in a tracking camera device for tracking anobject that is imaged by a camera and captured within a movementdetecting area, the tracking camera device comprising: the movementdetecting area including a plurality of detecting areas; each of thedetecting areas including a plurality of detecting blocks; anintegrating means for integrating pixel data for each of the detectingblocks; a first determining means for determining a plurality ofdetecting blocks corresponding to the object based on a result ofintegration; a second determining means for determining a firstdetecting area including the most of the first detecting blocks; and acontrol means for controlling a position of the camera to a direction ofthe first detecting area.

Accordingly, the integrating means integrates, for example,chrominance-related data for each detecting block included in themovement detecting area. Based on a result of the integration, the firstdetermining means determines a plurality of first detecting blockscorresponding to an object. That is, the first determining means, forexample, calculates a correlation value of the integration result to apreviously-registered reference value, and compares the correlationvalue with a threshold to determine a first detecting block according toa result of the comparison. The second determining means then determinesa first detecting area that contains the most first detecting blocks.The control means, in turn, controls the camera to a direction of thefirst detecting area.

Therefore, according to this invention, since the camera position iscontrolled to a direction of a first detecting area containing the mostfirst detecting blocks, it is possible to stabilize the camera positionwhen an object is finely moving or so.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a prefered exemplary embodiment of thepresent invention;

FIG. 2 is an illustrative view showing a movement detecting area set ona screen;

FIG. 3 is an illustrative view showing detecting blocks;

FIG. 4 is an illustrative view showing a movement detecting area set onthe screen;

FIG. 5 is an illustrative view showing a plurality of detecting areasincluded in the movement detecting area;

FIG. 6 is an illustrative view showing part the operation of thepreferred exemplary embodiment shown in FIG. 1 to FIG. 5;

FIG. 7 is an illustrative view showing part of the operation of thepreferred exemplary embodiment shown in FIG. 1 to FIG. 5;

FIG. 8 is an illustrative view showing part of the operation of thepreferred exemplary embodiment shown in FIG. 1 to FIG. 5;

FIG. 9 is a flowchart showing part of operation shown in FIG. 1 to FIG.8; and

FIG. 10 is a flowchart showing a subroutine of the flowchart shown inFIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 a preferred exemplary embodiment of the presentinvention will be explained. A tracking camera device 10 in thisembodiment includes a camera 12 that images an object to output digitaldata on a pixel-by-pixel basis. This digital data is signal digital datacontaining chrominance signals such as y, r−y, b−y signals. Thesesignals are integrated for each detecting block 16 as shown in FIG. 2,by an integrated data detecting circuit 14. Explaining the detectingblocks 16 using FIG. 2 and FIG. 3, the detecting blocks 16 are set tohave vertically 8 blocks and horizontally 8 blocks, i.e. totally 64blocks, within a movement detecting area 20 set on a screen 18. Eachdetecting block 16 contains pixels in number of i×j. A detecting block16, positioned at (m, n)=(5, 4), is taken as a particular detectingblock 16 a. The detecting block 16 set in this manner has integrateddata as expressed by Equation 1. $\begin{matrix}{{Y_{mn} = {\sum\limits_{ij}y_{mn}}}{{RY}_{mn} = {\sum\limits_{ij}\left( {r - y} \right)_{mn}}}{{BY}_{mn} = {\sum\limits_{ij}\left( {b - y} \right)_{mn}}}} & \left\lbrack {{Equation}\quad 1} \right\rbrack\end{matrix}$

A tripod-head control circuit 16 first registers integrated data as to aparticular detecting block 16 a as a reference value, and then receivesintegrated data concerning each detecting block 16. Then, a calculationis made for a correlating value D_(mn) of between the integrated datapreviously registered and the integrated data thereafter given,according to Equation 2. Further, the correlated value D_(mn) iscompared with a predetermined threshold to thereby determine a detectingblock 16 lower than the threshold, i.e. a first detecting block.

D _(mn) =|Y _(mn) −Y|+|RY _(mn) −RY|+|By _(mn) −BY|  [Equation 2]

Y, RY, BY: registered integrated data

The tripod-head control circuit 16 further determines a detecting area22 containing the most first detecting blocks, i.e., a first detectingarea, among a plurality of detecting areas arranged in the movementdetecting area 20, as shown in FIG. 4. Here, the plurality of detectingareas 22 are arranged such that each area partly overlaps with anadjacent detecting area 22 except for a center in the movement detectingarea 20, as shown in FIG. 4 and FIG. 5.

Consequently, if integrated data on a chest of a person shown in FIG. 6is registered at a certain field, then at a next field a hatched portionshown in FIG. 7 is determined as a first detecting block based on theintegrated data detected at this field and the integrated chrominancedata being registered. Further, a hatched portion shown in FIG. 8 isthen determined as a first detecting area. The tripod-head controlcircuit 16 supplies to a drive device 18 a tripod-head control signaldepending upon a position of the first detecting area so that the drivedevice 18 makes control on a tripod head 20. Consequently, the camera 12is controlled in position to a direction of the first detecting area.Incidentally, in the case of FIG. 8, the camera 12 keeps stable withoutshifting its position.

The tripod-head control circuit 16 is configured by a micro-computer, toprocess according to flowcharts shown in FIG. 9 and FIG. 10. That is, itis determined at a first step S1 whether a tracking switch 22 a isturned on or not. If “NO”, the process proceeds to a next field process,while if “YES”, the process is consideration as in a tracking mode andit is determined at a step S3 whether it is in a waiting state forintegrated chrominance data of a particular detecting block 16 a or not.If “YES”, it is determined at a step S5 whether a registering switch 22b is turned on or not. If the determination here is “NO”, the processproceeds to a next field process, while if “YES”, the integrated data isregistered at a step S7 and the process proceeds to a next field. On theother hand, if “NO” at the step S3, a first detecting block isdetermined at a step S9, a first detecting area is determined at a stepS11, and a tripod-head control signal is generated at a step S13. Thenthe process proceeds to the next field process.

At the step S9, the tripod-head control circuit 16 makes processingaccording to a subroutine shown in FIG. 10. That is, a correlation valueD_(mn) is first detected by using Equation 2 at a step S901, and it isthen determined at a step S903 whether the correlation value D_(mn)≦athreshold or not. If “YES”, the detecting block 16 is determined as afirst detecting block at a step S905, and the process proceeds to a stepS907. However, if “NO”, the process directly proceeds to the step S907.At the step S907 it is determined whether all the detecting blocks havebeen completed of processing or not. If “NO”, the process returns to thestep S901, while if “YES”, the process returns.

According to this embodiment, detection is made for a first detectingarea containing the most first detecting blocks to which direction thecamera 12 is controlled in position. Accordingly, when an object ismoving finely, the first detecting area will be always positioned at acenter, thereby making it possible to stabilize the position of thecamera 12.

Incidentally, in the preferred exemplary embodiment the digital data ofthe y, r−y and b−y signals were employed to detect a first detectingblock. However, it is of course possible to use digital data of r, g andb signals or digital data of y, cb and cr signals. Here, integrated dataas to r, g and b signals can be expressed by Equation 3, and acorrelation value thereof is represented by Equation 4. Also, integrateddata as to y, cb and cr signals is expressed by Equation 5, and acorrelation value thereof is by Equation 6. $\begin{matrix}{{R_{mn} = {\sum\limits_{ij}r_{mn}}}{G_{mn} = {\sum\limits_{ij}g_{mn}}}{B_{mn} = {\sum\limits_{ij}b_{mn}}}} & \left\lbrack {{Equation}\quad 3} \right\rbrack\end{matrix}$

 D _(mn) =|R _(mn) −R|+|G _(mn) −G|+|B _(mn) −B|  [Equation 4]

R, G, B: registered integrated data $\begin{matrix}{{Y_{mn} = {\sum\limits_{ij}y_{mn}}}{{Cb}_{mn} = {\sum\limits_{ij}{Cb}_{mn}}}{{Cr}_{mn} = {\sum\limits_{ij}{Cr}_{mn}}}} & \left\lbrack {{Equation}\quad 5} \right\rbrack\end{matrix}$

 D _(mn) =|Y _(mn) −Y|+|Cb _(mn) −Cb|+|C _(mn) −Cr|  [Equation 6]

Y, Cb, Cr: registered integrated data

Further, where using digital data of normalized chrominance signals suchas (r−y)/y and (b−y)/y signals; r/y, g/y and b/y signals; c_(b)/y andc_(r)/y signals, there is no variation in hue in an image captured bythe camera 12 even if there is variation in brightness. Accordingly, itis possible to successfully track an object even when there is change inamount of solar light or variation in brightness due to entering intoand outing from a room or the like. The integrated data and correlationvalue, when using digital data of (r−y)/y and (b−y)/y signals, arerespectively expressed by Equation 7 and Equation 8. The integrated dataand correlation value, when using digital data of r/y, g/y and b/ysignals, are respectively represented by Equation 9 and Equation 10. Theintegrated data and correlation value, when using digital data of cb/yand cr/y signals, are respectively expressed by Equation 11 and Equation12. $\begin{matrix}{{\left\{ {\left( {R - Y} \right)/Y} \right\}_{mn} = {\sum\limits_{ij}\left\{ {\left( {r - y} \right)/y} \right\}_{mn}}}{\left\{ {\left( {B - Y} \right)/Y} \right\}_{mn} = {\sum\limits_{ij}\left\{ {\left( {b - y} \right)/y} \right\}_{mn}}}} & \left\lbrack {{Equation}\quad 7} \right\rbrack\end{matrix}$

 D _(mn) =|{R−Y}/Y} _(mn)−(R−Y)/Y|+|{B−Y}/Y} _(mn)−(B−Y)/Y|  [Equation8]

(R−Y)/Y, (B−Y)/Y: registered integrated data $\begin{matrix}{{\left( {R/Y} \right)_{mn} = {\sum\limits_{ij}\left( {r/y} \right)_{mn}}}{\left( {G/Y} \right)_{mn} = {\sum\limits_{ij}\left( {g/y} \right)_{mn}}}{\left( {B/Y} \right)_{mn} = {\sum\limits_{ij}\left( {b/y} \right)_{mn}}}} & \left\lbrack {{Equation}\quad 9} \right\rbrack\end{matrix}$

 D _(mn)=|(R/Y)_(mn) −R/Y|+|(G/Y)_(mn) −G/Y|+|(B/Y)_(mn)−B/Y|  [Equation 10]

R/Y, G/Y, B/Y: registered integrated data $\begin{matrix}{{\left( {{Cb}/Y} \right)_{mn} = {\sum\limits_{ij}\left( {c_{b}/y} \right)_{mn}}}{\left( {{Cr}/Y} \right)_{mn} = {\sum\limits_{ij}\left( {c_{r}/y} \right)_{mn}}}} & \left\lbrack {{Equation}\quad 11} \right\rbrack\end{matrix}$

 D _(mn)=|(Cb/Y)_(mn) −Cb/Y|+|(Cr/Y)_(mn) −Gr/Y|  [Equation 12]

Cb/Y, Cr/Y: registered integrated data

Incidentally, the figure pictures employed in FIG. 6 to FIG. 8 toexplain this embodiment are those quoted from a software “Hanako” madeby Justsystem Corporation.

What is claimed is:
 1. A tracking camera device for tracking an object,comprising: a first former for forming a plurality of detecting blockson a screen; a second former for forming a plurality of fixed detectingareas arranged on the screen simultaneously in a manner such that eachof the detecting areas includes two or more detecting blocks out of saidplurality of detecting blocks; an integrator for integrating pixel datafor each of said detecting blocks; a first determiner for determining aplurality of detecting blocks corresponding to the objected base on aresult of integration; a second determiner for controlling a position ofsaid camera to a direction of said first detecting area, whereinwhenever said first detecting area is changed to another detecting area,said controller controls the position of said camera to a direction ofsaid another area, thereby tracking the object on an area-by-area basis.2. A tracking camera device according to claim 1, wherein said firstdetermining means includes a calculating means for calculating acorrelation value of the calculation result to a reference valuepreviously registered, a comparing means for comparing the correlationvalue with a threshold, and a detecting block determining means fordetermining the first detecting blocks according to a result ofcomparison.
 3. A tracking camera device according to claim 1 or 2,wherein the detecting areas are arranged so as to partly overlap withone another except for a center of said movement detecting area.
 4. Atracking camera device according to claim 1 or 2, wherein the pixel datacontains chrominance-related data.
 5. A tracking camera device accordingto claim 3, wherein the chrominance-related data contains chrominancesignal data.
 6. A tracking camera device according to claim 3, whereinthe chrominance-related data contains normalized chrominance signaldata.